All went well until I let mint updater download and install 154 (FFS!) updates. Now my on-board sound (geforce2, so nothing new or fancy) is not recognized. If I boot the old (i.e. original) kernel it works fine. Is this a mint issue or an ubuntu one? Is it a known issue? to whom do I file a bug report?

If you had a kernel update you must have updated level 4 and/or 5 which is not recommendedSure it fixes a security problem which however is no problem for most of us....It is to be expected that updating the kernel breaks something and you may have to reinstall some driverHowever geforce2 is not a sound card - it's a graphics card....